OK, let's do this. We've got 5488 and 3111 and we're adding them all together.

Step 1: We'll start by adding the digits 8 & 1 in column 1 and get 9.

Step 2: We'll start by adding the digits 8 & 1 in column 2 and get 9.

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5488 + 3111 = 8599.

